Communication Between a WebServer and WinForm Application (Dynamic IP)

[iPrank]

Sorry for late reply.

In this situation WCF will not work (I tested it.). Or hosting my own embedded website/IIS will not work either. That is the limitation of my client's ISP.
Just to clarify, I want this communication like this:

Viewer's Browser (request) -> Remote Website (send command) -> Remote Computer (send data) -> Remote Website (prepare page) -> Viewer's Browser (show page)

And I agree with you about the Dynamic IP thing. It is better to push the remote computer's IP to the server every 5min or so.

Edit:
The following text may help to understand my current method more clearly:

Browser: Request-------------------------------------------------------------------------------------------------------------------------> show page
website: -------Save command to db ------- wait ----------- wait ------ wait ----------> Get submitted data from database -> prepare page
Remote comp: (polling)----------> Got Pending command -> Get Data -> post data to db --> poll again